1,720,955 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Die Rolle des EGFR/HER2-Signalwegs in Gehirnmetastasen des Mammakarzinoms
No full textGehirnmetastasen repräsentieren als Endstadium von Krebserkrankungen die häufigste Art von Tumoren des zentralen Nervensystems mit extrem schlechter Prognose und gelten derzeit als unheilbar. Neben Lungenkrebs sind Mammakarzinome die zweithäufigste Ursache für Gehirnmetastasen. Bei der Diagnosestellung des Primärtumors liegt häufig bereits eine sogenannte minimale residuelle Krebserkrankung im Zielorgan vor, die ggf. durch Therapeutika nicht erreicht wird und zu Metastasen auswachsen kann. Um die Metastasenentstehung zu verhindert, ist eine frühe Diagnose der Mammakarzinomerkrankung von außerordentlicher Bedeutung. Die genaue molekulare Basis der Gehirnmetastasierung ist nicht geklärt. Der unterhalb der Rezeptortyrosinkinasen EGFR und HER2 liegende PI3K-Signalweg reguliert diverse an der Tumorgenese beteiligte Zellfunktionen. Die Effizienz der Therapie könnte durch eine kombinierte Inhibition mehrerer Proteine desselben oder in parallelen Signalwegen deutlich gesteigert werden, daher sind sie von außerordentlicher klinischer Bedeutung. Diese Arbeit ist die erste vergleichende Studie, die sich der Untersuchung von EGFR, HER2, PTEN und PIK3CA in verschiedenen Subgruppen primärer Mammakarzinome, Gehirnmetastasen sowie Metastasen in andere Organe gemeinsam zum Ziel gesetzt hat. Es wurden Analysen der Kopienanzahl , des Mutationsstatus der Proteinspiegel durchgeführt.
In dieser Arbeit konnte nachgewiesen werden, dass EGFR- und PTEN-Alterationen signifikant mit einer Gehirnmetastasierung assoziiert sind. Ein PTEN-Verlust scheint durch allelische Imbalanz, Mutationen und andere Mechanismen hervorgerufen zu werden. Ferner schließen sich Alterationen von HER2 und EGFR oder PTEN nahezu aus. Dies legt eine Untergliederung der untersuchten Proteine in drei Gruppen nahe: EGFR/PTEN-alterierte Mammakarzinome ohne Hormonrezeptor- und HER2-Expression mit einer ausgeprägten Organotropie für das Gehirn, HER2-exprimierende Fernmetastasen bildende bzw. PIK3CA-mutierte Primärtumore mit einer guten Prognose. Nur eine der Gehirnmetastasen wies keine Alterationen in allen analysierten Proteinen auf. Dies führt zu der Schlussfolgerung, dass fast alle Patientinnen mit Gehirnmetastasen von einer kombinierten Anwendung neuartiger, gegen Mitglieder des EGFR/HER2-Signalwegs gerichteter Therapeutika profitieren könnten.
Die Analyse der Rolle von PTEN in der Gehirnmetastasierung des Mammakarzinoms per Überexpression in aggressiven MDA-MB-231 BR Zellen ergabeine verringerte AKT-Aktivierung und Proliferation sowie Migration, was einem weniger aggressiven Phänotyps entspricht. Die Migrationsfähigkeit der Tumorzellen wurde PTEN-abhängig durch Gliaspezies induziert.
Die translationalen und funktionellen Ergebnisse deuten eine mögliche PTEN-abhängige Veränderung des Tumorzellphänotyps durch Interaktion mit dem Gehirnmilieu an, der die Besiedlung des Zielgewebes unterstützt.Brain metastases represent the final stage of cancerous diseases and are so far incurable. Besides lung cancer, breast cancer is the most common cause for brain metastases. The dissemination of single tumor cells from the primary tumor is as an early step in the metastatic cascade. Minimal residual disease is thus already present at distant site of relapse at time of primary tumor diagnosis. These cells remain undetected and may be inaccessible for therapeutics due to the non-proliferative state of the cells. An early diagnosis of breast cancers is of tremendous importance in order to prevent the formation of metastases. The exact molecular mechanism responsible for brain metastasis is still unclear. However, diverse cell functions involved in tumorigenesis are regulated by the PI3K pathway, which can be activated by the receptor tyrosine kinases EGFR and HER2. For maximal efficiency of treatment, combined targeting of multiple proteins of the same or parallel pathways may be potentially useful and thus be of clinical significance. This thesis is the first comparative study of EGFR, HER2, PTEN and PIK3CA in different subgroups of primary and metastatic breast cancer patients including brain and other metastases. Copy number variations, mutations and protein levels were determined. This study revealed a significant association between EGFR and PTEN alterations and the presence of brain metastasis. PTEN loss was shown to be mainly caused by allelic imbalance followed by mutations. Alterations of HER2 and EGFR were found to be almost mutually exclusive. Therefore, patients can be categorized into three groups: EGFR/PTEN-alterated hormone receptor and HER2 negative (triple-negative) tumors possessing a distinct organ-specific homing to the brain, HER2 overexpressing tumors generally associated with distant metastasisand PIK3CA mutant primary tumors with a good prognosis. Importantly, only one of the studied brain metastases samples harbored no alterations in any of the analyzed proteins. Therefore, these results suggest that almost all brain metastases patients would benefit from a combined use of novel targeted therapies against EGFR/HER2 pathway members.
The translational results of this thesis suggest brain as favored distant site for cells harboring EGFR/PTEN alterations due to its specialized microenvironment. The functional analysis of PTEN\'s role in breast cancer brain metastasis by overexpression in the highly aggressive MDA-MB-231 BR cell line showed decreased AKT activation and proliferation as well as diminished migration. Overexpression of PTEN thus caused a less aggressive phenotype. PTEN-dependent tumor cell migration was induced by glia species.
Translational and functional results point to a possible PTEN-dependent switch of the tumor cell phenotype supporting the colonization of target tissue caused by brain microenvironment interaction
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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